Authorities in Southern California spotted 15 great white sharks swimming in the Pacific Ocean, prompting a helicopter crew with the Orange County Sheriff's Office to warn a group of paddleboarders and swimmers out of the ocean.

The sharks can be spotted on a nearly three-minute video posted on YouTube by the sheriff's office on Wednesday. Employees are heard discussing the sharks and the locations of people in the water.

"You are paddle-boarding next to approximately 15 great white sharks," the Associated Press reported Deputy Brian Stockbridge telling people in the water over a helicopter loudspeaker. "They are advising you exit the water in a calm manner. The sharks are as close as the surfline."

The area was put under a shark advisory, the Register reported that Marine Corps Base Camp Pendleton announced.

Orange County Lifeguards Chief Jason Young told the Register there were two reports of sharks in the area. There also were reports from people on the beach who saw the sharks, Young told the news organization.